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by Godel_unicode 1816 days ago
The manufacturer doesn't know this, nor is it easy to determine. Is the max turbo frequency on air the max? On water (if so with what size rad with which fans)? At what ambient temperature? Is the max including tau, if so does that max change when it's about to expire? What about if the CPU was on ln² but the user has run out and can't add more to the cooling pot?

Every one of those numbers is different, and frequently the only way to determine if a frequency is possible to use for stable operations is to try it and see.
1 comments
dataflow 1816 days ago
No, you're just making this hard. Just imagine the CPU decided it wouldn't deliberately throttle its frequency to save power. Obviously nothing stands in its way of doing that; that's what it would do if they didn't deliberately tell it otherwise. Now what frequency would it execute the next cycle at? Obviously it decides on some frequency, and it does that without you telling it whether it's air or water cooled. Whatever number it would decide on: use that number.
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Godel_unicode 1816 days ago
Sometimes reality is hard :) One source of CPU throttling which you appear to be ignoring is temperature. Another is platform power delivery. Both are not always knowable by the CPU in advance. The CPU obviously doesn't "decide on a number" by itself. Sometimes it asks for a certain voltage but because of Tau it gets a lower one. Sometime it starts to boost because of demand only to immediately thermal throttle and run slower.

You cannot deterministically know what max frequency the CPU could be running at in some future demand/power/temp state.

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